<!DOCTYPE html>
<html>
<head>
<script type="text/javascript">

function boom()
{
  var a = [];
  a[31] = undefined;
  a[40] = undefined;
  a[44] = {};
  a[45] = new XMLHttpRequest();
  a[48] = new XMLHttpRequest();
  a[53] = XMLHttpRequest.prototype;
  a[53].__proto__ = {};
  a[53].nodeType = 100;
  search(a, 41);
}


function search(a, start)
{
  var N = a.length;
  
  for (var j = start; j < N; ++j) {
    var e = a[j];
    if (typeof e == "object" && "nodeType" in e && e.nodeType == 99)
      return j;
  }

  return null;
}

</script>
</head>
<body onload="boom();"></body>
</html>
